Edward is a wise blue tender engine.
Season 1 - Luke and the Special Party (mentioned), Races, Paxton Helps Out (cameo), Where's BoCo?, Bears (cameo), Dave the Diesel, and James and the Ice Cream
Season 2 - The Magic Railroad, Tim and Tom, Daisy and the Chickens (cameo), Sodor Blackout (cameo), Sodor Snow Storm!, The Bees' Knees (cameo), Hiro goes Home, Off to the Scrapyards, and Thomas and the Christmas Surprise (cameo)
Season 3 - Apples, The Rude Truck, Red Paint (cameo), Replacing the Logging Locos The Mail Depot (cameo), Out of the Mine, The Adventure, Musical Whistles, and Snowmen
Season 4 - The Return of D199 (cameo), Henry and the Coal (does not speak), and The Trouble with Trucks
Season 5 - James and Dennis
He is likely to appear in Season 6.